@article {482,
	title = {Sustained removal of uranium from contaminated groundwater following stimulation of dissimilatory metal reduction.},
	journal = {Environ Sci Technol},
	volume = {42},
	year = {2008},
	month = {2008 Apr 15},
	pages = {2999-3004},
	abstract = {Previous field studies on in situ bioremediation of uranium-contaminated groundwater in an aquifer in Rifle, Colorado identified two distinct phases following the addition of acetate to stimulate microbial respiration. In phase I, Geobacter species are the predominant organisms, Fe(III) is reduced, and microbial reduction of soluble U(VI) to insoluble U(IV) removes uranium from the groundwater. In phase II, Fe(III) is depleted, sulfate is reduced, and sulfate-reducing bacteria predominate. Long-term monitoring revealed an unexpected third phase during which U(VI) removal continues even after acetate additions are stopped. All three of these phases were successfully reproduced in flow-through sediment columns. When sediments from the third phase were heat sterilized, the capacity for U(VI) removal was lost. In the live sediments U(VI) removed from the groundwater was recovered as U(VI) in the sediments. This contrasts to the recovery of U(IV) in sediments resulting from the reduction of U(VI) to U(IV) during the Fe(III) reduction phase in acetate-amended sediments. Analysis of 16S rRNA gene sequences in the sediments in which U(VI) was being adsorbed indicated that members of the Firmicutes were the predominant organisms whereas no Firmicutes sequences were detected in background sediments which did not have the capacity to sorb U(VI), suggesting that the U(VI) adsorption might be due to the presence of these living organisms or at least their intact cell components. This unexpected enhanced adsorption of U(VI) onto sediments following the stimulation of microbial growth in the subsurface may potentially enhance the cost effectiveness of in situ uranium bioremediation.},
	keywords = {Acetates, Adsorption, Bacteria, Colorado, Geologic Sediments, Oxidation-Reduction, RNA, Ribosomal, 16S, Sulfates, Uranium, Water Pollutants, Radioactive, Water Supply},
	issn = {0013-936X},
	author = {N{\textquoteright}guessan, Lucie A and Vrionis, Helen A and Resch, Charles T and Long, Philip E and Lovley, Derek R}
}
@article {529,
	title = {Potential for quantifying expression of the Geobacteraceae citrate synthase gene to assess the activity of Geobacteraceae in the subsurface and on current-harvesting electrodes.},
	journal = {Appl Environ Microbiol},
	volume = {71},
	year = {2005},
	month = {2005 Nov},
	pages = {6870-7},
	abstract = {The Geobacteraceae citrate synthase is phylogenetically distinct from those of other prokaryotes and is a key enzyme in the central metabolism of Geobacteraceae. Therefore, the potential for using levels of citrate synthase mRNA to estimate rates of Geobacter metabolism was evaluated in pure culture studies and in four different Geobacteraceae-dominated environments. Quantitative reverse transcription-PCR studies with mRNA extracted from cultures of Geobacter sulfurreducens grown in chemostats with Fe(III) as the electron acceptor or in batch with electrodes as the electron acceptor indicated that transcript levels of the citrate synthase gene, gltA, increased with increased rates of growth/Fe(III) reduction or current production, whereas the expression of the constitutively expressed housekeeping genes recA, rpoD, and proC remained relatively constant. Analysis of mRNA extracted from groundwater collected from a U(VI)-contaminated site undergoing in situ uranium bioremediation revealed a remarkable correspondence between acetate levels in the groundwater and levels of transcripts of gltA. The expression of gltA was also significantly greater in RNA extracted from groundwater beneath a highway runoff recharge pool that was exposed to calcium magnesium acetate in June, when acetate concentrations were high, than in October, when the levels had significantly decreased. It was also possible to detect gltA transcripts on current-harvesting anodes deployed in freshwater sediments. These results suggest that it is possible to monitor the in situ metabolic rate of Geobacteraceae by tracking the expression of the citrate synthase gene.},
	keywords = {Acetates, Citrate (si)-Synthase, Deltaproteobacteria, DNA, Ribosomal, Electrodes, Ferric Compounds, Fresh Water, Geobacter, Geologic Sediments, Petroleum, Phylogeny, RNA, Ribosomal, 16S, Uranium, Water Pollutants, Chemical, Water Pollutants, Radioactive},
	issn = {0099-2240},
	doi = {10.1128/AEM.71.11.6870-6877.2005},
	author = {Holmes, Dawn E and Nevin, Kelly P and O{\textquoteright}Neil, Regina A and Ward, Joy E and Adams, Lorrie A and Woodard, Trevor L and Vrionis, Helen A and Lovley, Derek R}
}
@article {542,
	title = {Resistance of solid-phase U(VI) to microbial reduction during in situ bioremediation of uranium-contaminated groundwater.},
	journal = {Appl Environ Microbiol},
	volume = {70},
	year = {2004},
	month = {2004 Dec},
	pages = {7558-60},
	abstract = {Speciation of solid-phase uranium in uranium-contaminated subsurface sediments undergoing uranium bioremediation demonstrated that although microbial reduction of soluble U(VI) readily immobilized uranium as U(IV), a substantial portion of the U(VI) in the aquifer was strongly associated with the sediments and was not microbially reducible. These results have important implications for in situ uranium bioremediation strategies.},
	keywords = {Acetates, Biodegradation, Environmental, Deltaproteobacteria, Fresh Water, Geologic Sediments, Oxidation-Reduction, Solubility, Uranium, Water Pollutants, Radioactive},
	issn = {0099-2240},
	doi = {10.1128/AEM.70.12.7558-7560.2004},
	author = {Ortiz-Bernad, Irene and Anderson, Robert T and Vrionis, Helen A and Lovley, Derek R}
}
